Updated Invoicing APIs

- Updated Model objects.
- Updated Samples.
- Updated Tests.

lib/PayPal/Api/PaymentSummary.php

@@ -0,0 +1,65 @@
+<?php
+
+namespace PayPal\Api;
+
+use PayPal\Common\PayPalModel;
+
+/**
+ * Class PaymentSummary
+ *
+ * Payment/Refund break up
+ *
+ * @package PayPal\Api
+ *
+ * @property \PayPal\Api\Currency paypal
+ * @property \PayPal\Api\Currency other
+ */
+class PaymentSummary extends PayPalModel
+{
+    /**
+     * Total Amount paid/refunded via PayPal.
+     *
+     * @param \PayPal\Api\Currency $paypal
+     * 
+     * @return $this
+     */
+    public function setPaypal($paypal)
+    {
+        $this->paypal = $paypal;
+        return $this;
+    }
+
+    /**
+     * Total Amount paid/refunded via PayPal.
+     *
+     * @return \PayPal\Api\Currency
+     */
+    public function getPaypal()
+    {
+        return $this->paypal;
+    }
+
+    /**
+     * Total Amount paid/refunded via other sources.
+     *
+     * @param \PayPal\Api\Currency $other
+     * 
+     * @return $this
+     */
+    public function setOther($other)
+    {
+        $this->other = $other;
+        return $this;
+    }
+
+    /**
+     * Total Amount paid/refunded via other sources.
+     *
+     * @return \PayPal\Api\Currency
+     */
+    public function getOther()
+    {
+        return $this->other;
+    }
+
+}